1. Field of the Invention
The invention relates to excavating machines and, more particularly, relates to self-propelled excavating machines having a vehicle, a digging implement mounted on the vehicle, and a stowable discharge conveyor which is mounted on the vehicle and which is movable from an operative position in which the discharge conveyor discharges excavated materials into a truck to a transport position in which the discharge conveyor is confined within the dimensional confines of the vehicle.
2. Discussion of the Related Art
Excavating machines such as rock saws, chain trenchers, and road miners typically comprise a self-propelled vehicle having a digging implement mounted on the rear end thereof which excavates soil, rock, ore, or other materials as the vehicle travels in a forward direction. Digging implements have traditionally discharged materials on the ground in front of or beside the digging implement on the assumption that the excavated materials would be used as backfill for the trench. However, in recent times, governmental regulations and other considerations have required that the excavated materials be removed from the work site and that "clean" backfill be brought in from other sources. Removing materials excavated by traditional excavating machines requires that the materials be retrieved either manually or by a front-end loader or the like after the trenching operation is complete. The cost of such subsequent retrieval, coupled with the difficulty of retrieving all excavated materials without at least some of the materials falling back into the trench, has led increasingly to a demand for excavating machines which discharge excavated materials directly onto a truck positioned in front of or beside the vehicle.
A particularly attractive arrangement for conveying excavated materials to a truck from a digging implement is a so-called centerline conveyor assembly positioned on or near a longitudinal centerline of the vehicle. The typical centerline conveyor assembly includes a loading conveyor and a discharge conveyor. The loading conveyor receives excavated materials from the digging implement (either directly or indirectly via one or more intervening lateral conveyors) and conveys the excavated materials to a discharge end thereof located in the vicinity of the front end of the vehicle. The discharge conveyor has an inlet end positioned under the discharge end of the loading conveyor and extends forwardly from the front end of the vehicle to discharge excavated materials into a truck from a discharge end thereof. The typical discharge conveyor is swingable on a turntable or shaft so as to be capable of discharging materials onto a truck positioned on either side of the vehicle.
One disadvantage of discharge conveyors is that, in most instances, they extend ten feet or more in front of the excavating vehicle when in their longitudinally-centered position, rendering the overall length of the excavating machine unacceptable for transport. This problem could be alleviated by stowing the discharge conveyor, e.g., by swinging the discharge conveyor to the side of the loading conveyor. However, only limited side-to-side movement is possible (typically in an arc of about 180.degree. extending 90.degree. from each side of the longitudinal centerline of the vehicle) due to potential interference from the loading conveyor. This limited movement may reduce the overall length of the excavating machine, but unacceptably increases its width. Accordingly, transport of excavating machines having discharge conveyors has traditionally required the removal or at least partial disassembly of the discharge conveyors prior to transport.